Viral proteins assemble into capsids rapidly and reproducibly in many different organisms and environments. This project is designed to determine what features of protein-protein interactions are required for such robust assembly. Identifying the requirements for robust assembly could play a critical role in antiviral strategies as well as in the development of viral vectors for gene therapy. More significantly, organization of basic units into well defined, large scale structures is integral to many biological systems. Hence, understanding assembly at a fundamental level for a relatively simple system, such as a virus capsid, could have broad applications throughout biology. In order to capture essential details of individual proteins while describing large scale assembly processes, a hierarchy of simulations and theoretical methods is proposed. The theoretical efforts at each level are coupled to experiments that probe the same phenomena. This endeavor is viewed as a springboard for the development of a general algorithm for systematically coarse-graining in assembly processes.